Electron beam collimation from an all-metal double-gate 40 000 nanotip array: Improved emission current and beam uniformity upon neon gas conditioning

Abstract

In this study, the authors characterized field emission for stacked-double-gate all-metal field emitter arrays (FEAs) consisting of 40 000 nanotips. After careful conditioning of the FEAs under ultrahigh vacuum and in low-pressure neon gas ambient, the authors were able to produce a highly collimated beam with a current of ∼50 μA which showed an improved beam homogeneity. The beam rms radius reduced by a factor 10 and the transverse energy spread was reduced to well below 1 eV.